高疏水表面的聚偏氟乙烯中空纤维膜制备方法研究

Preparation of polyvinylidene fluoride hollow fiber membrane with highly hydrophobic surface

采用稀溶液相转化法制备出小粒径的聚偏氟乙烯(PVDF)粒子,然后通过超滤方法将其涂覆在PVDF基膜表面上,得到了高疏水性表面的PVDF疏水膜.初步考察了凝固浴组成和凝固浴温度等稀溶液相分离条件对PVDF粒子的形成以及疏水膜性能的影响.结果表明,通过稀溶液相转化方法可以在基膜表面构建微纳米结构,凝固浴组成对改性疏水膜的表面微纳米结构影响很大,以质量分数为60%DMAc水溶液为凝固浴条件下得到的疏水膜接触角最高,达到144.9°,较基膜的接触角80°显著提高;凝固浴组成对疏水膜的透气系数和透水压力也有影响,透水压力由0.24 MPa提升至0.28 MPa;凝固浴组成对改性后疏水膜的孔径没有明显影响;随着凝固浴温度的升高,接触角呈增大趋势.

Dilute solution phase inversion method was used in this paper to prepare nano-size particles of polyvinylidene fluoride（PVDF）,which were then coated on the surface of PVDF hollow fiber membrane to form a highly hydrophobic surface of PVDF membrane by ultrafiltration process.The effects of the composition of the coagulation bath,the temperature of the coagulation bath and other conditions of the dilute solution phase separation on the hydrophobicity of modified PVDF membrane were investigated.The results showed that the surface with a micro and nano structures could be constructed on the support membrane by ultrafiltrating the nano-size particles prepared with the dilute solution phase inversion method and its property was affected greatly by the composition of the coagulation bath.When the coagulation bath composition was 60% DMAc aqueous solution,the prepared particles had the best nanostructure,the contact angle of hydrophobic membrane prepared with these particles was highest,reaching 144.9°which was much higher than the 80°contact angle of the support membrane.The gas permeability coefficient and the water permeability pressure of the hydrophobic membrane were also affected by the coagulation bath composition,the water permeable pressure increased from 0.24 MPa to0.28 MPa;the composition of the coagulation bath had no obvious effect on the pore size of the hydrophobic membrane.The contact angles of the hydrophobic membranes which were made from the particles prepared with different coagulation temperatures had an increasing trend as the coagulation temperature increased.